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Do pilots intentionally crash in a simulator?
Are pilots allowed to intentionally crash inside the simulator? It is good for stress relief and seems like a fun way to do something you would never do on an actual aeroplane, with little to no consequence.
If not, why not?

I've done it in the shuttle simulator, when I was testing out a fix for the sim crashing at too high of an altitude on contingency aborts. But I am not a real pilot.

IIRC some C130 simulators in the UK in the late 1970s used a video camera to capture real-time images of a landscape model - seems rather primitive by today’s standards but there you go.  If a pilot crashed into something it would cause damage to the camera and landscape, so it was frowned upon.

I am referring to physical simulators, with real buttons, and not a FlightGear and laptop setup (which I use daily).

Does this answer your question? Do Flight Simulation Instructors stop the simulator before a simulated crash?

No, as that is for accidental crashes, and not ones done on purpose.

Flight training device still has all the realistic controls and switches but, unlike full flight simulator, it does not move.

As a layperson I'd be concerned if pilots were being conditioned to crash a plane (even a fake one) to "blow off steam".

Just a clarification - do you mean for the pilot to crash the simulated plane, or for the simulator to physically run out of travel and crash into a hard stop ?

If Andrew Wiggin had intentionally crashed in the simulator, that would have been rather awkward.

@Criggie I mean that the pilot regardlessly decides to crash, with no regard to simulator specifics.

As real simulator hours are expensive (and probably supervised), I highly doubt that an pilot crashes for fun. However the situation may be completely different for home simulators. Maybe watch the excellent movie "Sully (also known as Sully: Miracle on the Hudson)": Crashes are no fun for pilots.

If a pilot (or even a trainee pilot) doesn't understand the difference between real-life aviation and playing video games, maybe their license should be revoked until they demonstrate they are psychologically well enough to fly.

The Department of Homeland Security might want to keep a eye on a pilot training like that.

I have heard that the FAA actually frowns upon this ever since 9/11.  Some instructors also used to place pilots in unrecoverable windshear situations during training, but then it was decided that this is not a positive training scenario, and could reinforce incorrect attitudes regarding windshear.

I've intentionally crashed Full Flight Simulators, to demonstrate to the instructors that in a modern day FFS, crashing is a non-event. Basically just a stop of the real-time equation computations, a bit of a crash sound, and freeze of the visuals. The instructor then selects a new initial position, the sim resets at this position after the normal time period, and the training continues.
During normal flight training when type rated pilots demonstrate their skills in handling emergencies to prevent a crash, this does not happen of course. Unintentional crashes can take place during the type rating courses, when pilots who just graduated on a propeller plane are getting used to the speed of control and decision making of a passenger jet.
Yes indeed, crashing an older type sim could have lengthy consequences if the computers needed to be re-booted upon a crash. Not anymore.
Note: I'm talking about modern simulators with electric motion and control loading. Any event that kicks a hydraulic system off-line needs fade-in time for the re-engage.

I would also like to state that even in 'very' modern simulators (I work on cutting edge fighter pilot systems), mission computers are re-hosted on PCs. they often don't like being reset. crashing often means a full reset which sometimes can take up to 15 (or more) mins. It happens every day. Sometimes on purpose. But this type of behaviour isn't limited to just "older type sims". Doesn't mean it 'needs' to be that way but it is that way still

The ones I”m talking about had industrial PC host computers. A crash was handled in the software: detection of a sudden spike in flight path, upon which the flight dynamics computations were frozen, then re-initialised by the instructor. Never did the host need to reboot.

@Koyovis, the problem sometimes happens when the real firmware or complete sub-systems are used in the simulator. They are rarely designed to "understand" crash (or even "pause" for that matter), and might not continue correctly without a reset.

I've heard of pilots taking an hour the last day of training practicing crazy engine-out takeoff scenarios where you're lucky to make it back to the runway.  Sounds like a fun end of the day energy-management challenge where most people fail.

@NateLowry Yeah I did that in the 737NG simulator, crazy scenarios in a steep dive with the engines at idle, then start the pull-up at exactly the right moment for a neat touchdown. Part of a bet that I could get the plane on the ground faster, did so by touching down at the point where I took off, against the take-off direction, which is against standard practice of course. Can only be done in a sim. Exciting rides.

@Zeus The sim had aircraft hardware on board, I specifically remember the Honeywell EGPWS box. The sim was just tested and set-up specifically for minimum initialisation time no matter the pre-condition. We did not have to re-boot between training sessions.

One reason to deliberately crash in a simulator is to reconstruct an accident.
This happens once in a while during an accident investigation, as it's less dangerous (obviously) than trying to reconstruct the conditions of the accident in a real aircraft (if possible at all, as the investigators of course can't control the weather outside of the simulator.
But that's not done for fun, to blow off steam, or some other "I feel like it" moment by a pilot.

It certainly might be useful and justified to find the conditions that led to a crash, but even then, I doubt that someone would deliberately crash it. It would be at most one more case of "this might have caused the crash". As far as crashing "for the hell of it", I'm sure that whoever is paying for your time on the simulator (i.e., your airline employer) would not be amused. I suspect that the licensing authorities would not look kindly on the mental stability of a pilot who appears to be possibly suicidal (see GermanWings crash).

@PhilPerry deliberately recreating the exact conditions that caused a previous crash is IMO deliberately crashing. As the people doing it have good reason to do so their mental state won't be questioned if they do it in the context of investigating that previous crash.

jwenting, my point is that investigating why a crash happened may well result in a crash (as in real life), but hopefully the tester can work their way out of it ("it might have been avoided if the pilot had done X"). That's NOT deliberately crashing. As for doing it deliberately, I would hope that the simulator operator would report to the authorities anyone who seems to be crashing for no real cause, as they are obviously mentally ill. Note that's different from pushing the envelope or practicing in unsafe conditions.

@PhilPerry the investigators will run the scenario several times. First using the exact inputs they found the actual pilots used (if known) and then trying different things that might have prevented the accident.

I think I read that during the final real airworthiness test flights of the 737-Max, post-fixes, the pilots attempted to recreate a situation similar to the fatal crashes.

For a specific example where multiple tests were done in a simulator that resulted in "crashes", see the Miracle on the Hudson:
From Wikipedia (which has references to NTSB and other reports), emphasis added:

The NTSB used flight simulators to test the possibility that the flight could have returned safely to LaGuardia or diverted to Teterboro; only seven of the thirteen simulated returns to La Guardia succeeded, and only one of the two to Teterboro. Furthermore, the NTSB report called these simulations unrealistic: "The immediate turn made by the pilots during the simulations did not reflect or account for real-world considerations, such as the time delay required to recognize the bird strike and decide on a course of action." A further simulation, in which a 35-second delay was inserted to allow for those, crashed.

See also United 232.

But they didn't "intentionally crash" in the simulators, did they?

Not truly "intentionally crash". But my impression is that they went into the simulation knowing there was a high probability of crashing. Not exactly what the question asked, but similar to jwenting's answer, with specifics.

Welcome to Av.SE. That's a good example of a case when the pilots were entirely willing to "crash the simulator" for an entirely valid reason. I agree that it's a good answer to the question.

Crashed, in this case meaning: did not make the runway.

@Koyovis In the case of the Hudson, the real pilots did not make the runway, but they didn't crash, they performed a controlled ditching. But the simulations mostly resulted in (simulated) crashes.

I work in a company that builds simulators. Our customers have a lot of expectations, so we work hard to make the simulation adequate. The precision of the simulation of a crash is not, by far, what is most expected from our simulators. So we do not waste our time making it somewhat realistic. Moreover, to check that a simulation is realistic, it is compared to real aircraft behaviour. We do not find easily data for crashes to compare with, hopefully.
So, for our sims, this non-realistic feature is just here to inform that the aircraft can't fly anymore and that the lesson should be resumed.

I agree that professional flight simulators don't focus on "post-crash" simulation like fancy explosions and other animations that might be considered as "fun", but on "pre-crash" simulation (events that lead to a crash). Maybe those simulators even abort before the pane (or parts of it) hit the ground. Also I think it's a very hard part to simulate equipment failures is great detail. Maybe have a look at X-Plane: It may be some fun to do a "power slide" on the runway with an airliner, but it's most likely not realistic (as the tyres would be pulled off, I guess).

Why would a professional flight simulator (or the company that builds one) want to reproduce game like effects (ala xplane). That's not what those simulators are for.

While most simulators don't try and specifically replicate crashes, I have seen both developers and customers decide they need to "just see what happens when the plane crashes".  It is one of those things a lot of people will want to try.

Landed a sim of an aeroplane type I had not flown before a couple of months ago. My touchdown would have been too impactful on the landing gear, the sim conveyed this by freezing the visual and playing a crash sound. Then I could re-initiate to the glide slope to try again. The sim was built in 1993 - it had no problems with a hard landing crash, it only showed me that my landing skills need to be improved on this AC type.

Not aviation, but simulator related. In the 1960s the UK railways were transitioning from steam traction to electric and diesel. A lot of steam drivers needed retraining. They had to unlearn a lot of things to do with the 'feel' of the train in motion. A simulator was built, with a replica locomotive cab, with a movie screen in front. On this was projected a film of the route being trained. A mainframe computer was programmed to read the cab controls (speed and brake) to control the film speed, show appropriate readings on the dials in the cab (speed, brake air pressure, motor amps, etc) and also move the cab via hydraulic actuators in accordance with the calculated motions expected due to acceleration, deceleration, rounding curves, passing over switches, etc.
One driver, allegedly, braked too late at the end of a run in a terminal station with buffer stops, and the computer faithfully moved the cab in accordance with the deceleration, breaking the driver's nose against the windscreen.

It can't have moved the cab exactly in accordance with the acceleration and deceleration of a real locomotive - if it did then it would be a real locomotive.

@bdsl of course it didn't mimic exactly to the extent of replicating a collision authentically. That would be pointless, and if it did, a trainee driver might seriously injured or killed.

I wasn't so much thinking about not mimic to the extent of a collision - I was more just thinking not mimicking the acceleration to the extent of actually travelling from one end of the UK to the other.


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How does the F-35B not flip over during transition?

As the engine nozzle rotates, the lift-fan cannot. Wouldn't this imbalance of moments around the center of gravity result in the F-35 pitching up onto its back?
As can be seen at 5:14 in this video:

 the F-35B is capable of transitioning from vertical hover to horizontal flight.
It accomplishes this in part by gradually rotating the engine nozzle from the vertical position to the horizontal.
Let us assume that the throttle input stays constant in the following scenario:
As the nozzle rotates, the vertical component of its thrust is reduced (as the horizontal component increases) as
$$thrust_{horizontal} = thrust \cdot \cos(\theta)$$
$\theta$ being the angle between the jet exhaust and the vertical axis.
The problem is, the lift fan does not rotate.  And since it is attached by shaft to the engine, we assume it always rotates at the same RPM as the engine itself.
Therefore, the vertical component of lift of the lift fan does not change for a given throttle input, while the vertical component of the jet engine nozzle does!
So as the nozzle transition occurs, the thrust of the lift fan (ahead of the center of gravity) stays constant, but the vertical thrust behind the center of gravity (rear engine nozzle) reduces: shouldn’t this cause the aircraft to pitch upwards and flip onto its back?
Yet in the video the aircraft seems to pitch up only ten or so degrees (I assume due to the increased coefficient of lift on the wings) but otherwise stays flat in pitch.
The thrust of the lift fan must be somehow modulated to accomplish this, right?  If so how is this done if its shaft speed is tied to that of the engine?
Possible solutions:
1. As the aircraft’s forward velocity increases, the lift of the wings compensates for the reduced vertical lift of the rear engine nozzle.
2. The aircraft pitches up so as to deflect the angle of the lift fan from the vertical to match the angle between the engine nozzle and vertical.

"Let us assume that the throttle input stays constant in the following scenario:"  That is a really bad assumption to make on such an advanced aircraft.  Obviously, the nozzle thrust is adjusted to compensate for the changing nozzle angle.

That assumption was just made to simplify the formulation of the question. Of course I actual flight the throttle would be adjusted.

Please consider reviewing which answer you accepted.

To try and change lift by changing fan blade speed would be too slow to modify the lift for "tiny" and "delicate" changes in how the plane hovers.
Like a helicopter, the F-35 is able to maneuver in very small movements and change very fast (in fact likely better than a helicopter).
So the pilot can "nod" to you, and move around the front nose with tiny, delicate moves. So tiny movements by the F-35 and the flight stick are rapidly accepted by the flight computers.
Now a helicopter uses variable pitch blades to make rapid changes, which allows helicopters to achieve tiny, delicate, and fast "little" moves. So tiny fast changes in lift are required for these delicate moves.
Change of engine throttle to change fan lift would be far too slow (for the F-35, or for a helicopter).
To save weight, and complexity, the F-35 lift fans are counter rotating, and they are light weight carbon fiber.
So, to rapid change lift and have rapid tiny changes in lift, they simply change the area/size of the exit exhaust area of the lift fan.
Think of those "variable" nozzles much like a window shutter to let more or less light into a room.
The shutter looks like this:

So, you can open a bit more, or close a bit more.
However, when you close the shutter more, then where does the air go? It has to go somewhere! (remember, up to 20,000 lbs is created by that fan).
Well, there is a second set of doors that open right behind the one large fan lid.
That second set of doors can be seen here:

Those 2nd set of doors behind the big lift fan lid are to allow venting of the lift fan.
So you need a fast and delicate means to change lift fan output. So amazing and so tiny are these changes, that the pilot can "nod" the nose down a bit. Very tiny changes are achieved.
So to change the fan downforce you thus close or open the lift fan exit (exhaust) area doors. This can be closed or opened rather fast, and also by tiny amounts. This gives delicate control.
However, when you squeeze close this exit area, then the lift fan air has to go some place else, so it is vented out those doors right behind the big lift fan lid door.
So, if you close down the exit hole on the bottom of the F-35 fan, then that air takes another path – right out those 2nd set of doors.
9 out of 10 diagrams on the internet call that second set of doors an auxiliary inlet. However, that is NOT 100% correct. It should be called an auxiliary exhaust.
Now, to be fair, because the cold inlet turbine compressor is also exposed to that vent area, then no doubt that area likely remains "negative" pressure most of the time.
However, this is quite a brilliant design, since that lift fan exit area in general has some amount of "close" and thus "some" amounts of fan exit air is going to be vented (by-passed) right into that "box" behind the lift fan.
And that box just so happens to be right where the hungry for cold air turbine inlets of the massive F135 engine is. (What a nice design!)
So likely that area remains negative due to the compressor inlets. However, that area will go positive with most of the lift fan exhaust closed.
In this case, then those two doors are in fact a lift fan exhaust vent – not an intake vent!
I should also point out that due to vast amounts of cold air hitting the deck with this lift fan system, Lockheed engineers state that the overall deck temperatures are less than a Harrier when landing on the deck of a ship.
So while both Harrier and F-35 tend to heat up the decks on a vertical ship landing, the F-35 actually is less of a heating problem then is the Harrier for such vertical landings.
References to my statements:
From Lockheed:
https://www.lockheedmartin.com/content/dam/lockheed-martin/eo/documents/webt/F-35_Air_Vehicle_Technology_Overview.pdf
page 25:
quote:

With this system, nozzle thrust may be directed in an arc of 41.75-104
degrees (fore/aft aircraft coordinate system), at a rate of 40 degrees
per second.

Ok, so far, above ONLY talks about directing the down thrust.
But, we have this:

Independent control of the three VAVBN actuators provides the
capability to vary the nozzle throat area independent of the vector
angle

To save reading, we have:
VIGV = top intake part (variable )
VAVBN = bottom exit part (also variable).
So above states the VAVBN actuators (the EXIT PART OF THE FAN) can vary the nozzle throat area.
My claims:
Lift fan blades are NOT variable pitch.
There no evidence, no diagram, or ANY information of ANY kind in existence that CHANGES this claim of mine. I stand by this claim.
Lift exit fan can open/close or "vary" the fan output.
Again, the above document 100% supports and verifies my claim.
NOT verified:
My claim that when closing down the 20,000 lbs of fan vent flow, that flow HAS to go some other place, and I am claiming that flow goes to the air box behind. This is a SPECULATION on my part. I do believe this to be what occurs but I do NOT have a link or article that outright states this (some diagrams DO suggest this, but that would not be proof). So this claim of mine that fan air vents to the air box behind is NOT verified by me, and until I can provide solid evidence of this, then that claim should be taken with a grain of salt.
Edit 2
As for the speculation of air venting out of the fan box, this here is a photo.

It is "difficult" to tell if that is a vent door, but does seem to look like one. As noted - I am open to opinions on this - this right now thus is still a speculation on my part.

You are correct that the LiftFan blade pitch can be adjusted to vary the thrust of the fan. However, the latter half of your answer regarding the Aux Inlet doors is inaccurate. These doors open to increase airflow to the engine during hovering operations because the side-mounted fixed inlets don't provide enough airflow if the aircraft is not moving forward. Lift fan exhaust is directed out the bottom of the aircraft through a third set of doors, and is controlled by a set of movable guide vanes. LiftFan exhaust is not supposed to interact with engine intake -and in fact this can be dangerous!

The fan blades are NOT variable pitch. the amount of down thrust is controlled by the sent of "vanes or open/close doors". To reduce fan down thrust, you CLOSE the hole on the bottom. When you close that hole,  then WHERE does the air go? (answer: it goes out into the area exposed by the second set of doors behind the lift fan. The lift fan is NOT variable pitch.  To reduce down force, you close the hole on the bottom. If you close that hole, then the air HAS to go some other place - has to take some other path. That other path is right into the area with the two doors that open behind the fan

I have made no claim, no hint, or even no imply by omission that the intake doors vary their intake size. The set of shutter vanes I included in above as picture shows the exit door that can close or open. When you CLOSE that vent door, then the fan air HAS to go some place because it cannot escape DOWN out the bottom anymore. That air NOW takes a path into the box area with the two doors that open behind the lift fan. The downward force is not controlled by variable pitch - it is controlled by opening or closing the doors on the bottom. Close those doors, then air vents into box behind fan,

And no, cold air from the lift fan is NOT a problem for the engines to ingest. In fact, as I pointed out, as you close the exit vane on the bottom, the cold air from the lift fan is NOW being routed to the box behind the lift fan with the doors. As I stated, it ALSO turns out that box area has the f135 intake compressor blades exposed. This is a good thing, not a bad thing. The issue of “bad air” in regards to the Harrier is an issue because ingesting hot air will not only reduce power, but can cause a compressor stall. So YES the lift fan air in this case DOES go right to engine intakes.

If you could provide a source for your information that would greatly strengthen your answer.

One correction - the dorsal intake behind the lift fan intake is not the lift fan exhaust vent.  It is an auxiliary air intake for the engine to provide extra air during high power setting at low airspeeds where the intakes cannot do so.

An amusing anecdote on the performance of a hovering Harrier as a ground heater: a long time ago the UK RAF did a trial of using a disused WWII airfield as an "emergency" Harrier base. (The field was still in use as a transit camp for personnel but not for flying). They had a Harrier doing hovering tests over the ancient concrete runways to check for potential problems. Having "successfully" completed that exercise, the Harrier landed - and burst all its tires when they hit the hot concrete. Oops….

Article after article suggests that the f35 is somehow SO MUCH MORE hard on decks in terms of overheating then Harrier. And we see a round of articles stating the same for the v22. We then watch and see a v22 land on a grass field, hover and idle engines for 25 minutes with mansels pointed down on the ground. Harriers have landed and taken off from grass fields. I call this heat-gate, as military contactors are stating that 100's of millions of dollars of upgrades are required for ships that can handle the Harrier but not the f35. This is really a quest to grab more contractor dollars.

@AlbertD.Kallal It looks like the top paragraph on page 25 of ymb1's PDF link answers the OP pretty directly (minimizing thrust-thrust split). It's still unclear (to me, after reading the PDF) what the role of the top variable vanes is, and where the air goes when the flow is restricted. Or whether it has to go anywhere—remember it's a fan, not a positive-displacement pump. It's possible the restriction just increases the pressure in the fan duct and decreases the inflow.

The pdf refernced DOES however verify my claim that the exit vents ALSO can reduce the exit area. In fact my source was that article. So it verifies my claim of NOT having variable pitch fan blades, and also states that the exit vanes ALSO can restrict output. The ONLY part NOT verified is when exit vents restrict air, does the air take a path back to the air box behind? That IS a assumption on my part but I can't see how 20,000lbs of lift is JUST squeezed shut and not go anyplace. I will edit my post to kindly point out this is a assumption on my part.

I should point out that I labelled  the open doors as vent AREA, not lift fan exhaust. This label was on purpose, since I am claiming that fan air vents to this area, NOT that the doors are ONLY for this purpose.

@AlbertD.Kallal.  The label “ lift fan exhaust vent area” is wrong. This is the “auxiliary” intake for the main engine. It has absolutely no connection with the lift fan mass flow. See: https://arc.aiaa.org/doi/abs/10.2514/6.2013-218

@AlbertD.Kallal. To answer the question “where does the lift fan flow go when it’s closed down”: as the lift fan thrust decreases, the lift fan mass flow decreases. So, it doesn’t have to go anywhere different. It still goes in the top lift fan inlet, and out the VAVBN. But, you are correct, the lift fan blades are not variable pitch.

And how does the lift fan decrease the air flow? Well, you close down the bottom exit part - and that flow goes now is directed into that box with the open doors behind the lift fan. We established clear that the bottom exit of the lift fan is variable - so as you close it down then where is the air directed? We all agree that air flow is variable. But the question then is where is that extra air flow sent when you close down (restrict) the air flow out the bottom of the lift fan.

If you do a quick movement to lift up the nose or point it downwards you are varying the fan output by quite a bit. That rapid change in airflow has to go someplace - that place is now not bottom but is directed into that airbox behind. You  not changing the pitch of the blades - so air flow is not in fact decreasing but being re-directed someplace else.

“ Those 2nd set of doors behind the big lift fan lid are to allow venting of the lift fan.”  That is incorrect. Those are auxiliary air intake doors to provide extra air for the engine during lift fan  operation.  Whoever did that graphic screwed it up as well.

Your assumptions (constant thrust for both lift fan and exhaust) are wrong. From wikipedia:

"For pitch control, the areas of exhaust nozzle and LiftFan inlet are varied conversely to change the balance between them while maintaining their sum, and with constant turbine speed"

So yes, the thrust is modulated to accomplish this.

From what is available on the internet, the F35B's lift fan is more than just a simple shrouded fan. There is at least some variable guide vanes functioning as nozzle. So to answer your question, no, the lift from front and back seem to be completely (lift fan by variable guide vanes, engine nozzle by, well, a variable nozzle) adjustable.

Appricate the diagram. As noted, this shows the bottom box is "variable". Looking at the box, it does "hint" at when those vanes are closed, then vents on the shaft side would be where such air flow goes. As I stated in my post, this is the direction of the air when the vane box is closed that I "assume" the air goes, but it not 100% clear from the above. However, the above at least does verify my claim that the exit box is "variable" in output.

@AlbertD.Kallal no, the "vent" behind the inlet of the lift fan is a secondary inlet for the main engine because when the F35B hovers close to the ground the air on its side may be disturbed by the downwash reflecting off the ground thus it cannot breathe this 'dirty' air and need a secondary inlet on its dorsal side.

Not disputing that vent claim. However, like blow-out doors on the cowlings of the 707, or the Harrier, the air pressue goes negative and those spring loaded passive doors open to increase intake area for the cold compresser side to pull in more air. However, as the plane gathers speeds, then the air around the intakes goes positive, and those blow-in doors shut. I specific  labelled and used the term "lift fan exhaust area". If I am correct about the fan exhaust venting to that area, then I stand by my claim that that area will and can see positive air pressure.

The first diagram here shows what looks like "vents" on the bottom of the variable nozzles box - and they POINT in the direction of the air box behind the  lift fan. There are no such vent like structures on the side of that nozzle box, but it SURE looks like vents to the rear (or towards the air box). As I stated, if you close the output of 20,000 lbs of air, it has to go some place else. If you stop venting of that thrust down, then it goes rearward to the box behind. This means that area will (can) go positive air pressure, and at that point those two open doors are in fact venting air.

I am VERY open to that air does not vent from the fan area. However, when f35 is flying say at 80 knots with that big lid open, it going to catch a LOT of air, and force it down onto the fan, if the fan exits are closed, then it makes sense that the air now can flow to the air box behind. It is not 100% given that this occurs, and I am open to that the vanes on the lift fan system simply "close down" the air flow but it would make sense to vent the air back to the box area behind as you "close down" airflow though the fan system.

My understanding is that the lift fan (two sets of contra-rotating blades) is driven from the main engine via a permanently rotating drive shaft, but that the drive from the shaft to the lift fan is connected/disconnected from the lift fan via carbon clutch plates. In conventional flight it makes little sense to waste engine power driving the lift fan when not needed.
With regards to the moveable vanes beneath the lift fan - they do not ‘close’ like a set of shutters as has been suggested, but move through a limited arc to direct the lift fan thrust from vertically straight down for hovering to 45 degrees rearwards to add a proportion of thrust when transitioning to conventional flight.
It is these same vanes that can also rotate to 5 degrees forward to provide thrust to cause the aircraft to move backwards when hovering.
As the lift fan is driven at engine speed when hovering and transitioning, the lift fan inlet guide vanes on top of the lift fan vary the volume of air ingested by the lift fan and hence the thrust of the lift fan itself.
The balance between main engine exhaust thrust and lift fan thrust is co-ordinated by the digital engine control system.
After transitioning to conventional flight, the lift fan clutch disengages the lift fan from the engine-driven drive shaft and the lift fan ceases to rotate. Beneath the fuselage, the lift fan exhaust doors close (not the lift fan exhaust vanes).
The pair of doors on top of the fuselage are not vents, these are the AAIDs (auxiliary air intake doors) to allow increased air flow to the main engine during the hover (as noted in previous posts).
This is covered in the 2014 Air International F-35 special.

Those 2nd set of doors behind the big lift fan lid are to allow venting of the lift fan.
Incorrect. AAIDs - Auxiliary Air Inlet Doors - provide additional air to the F135 intake, not "venting of the lift fan".
"and an auxiliary inlet." F-35 Air Vehicle Technology Overview, page 14
"The exhaust is discharged through a thrust vectoring nozzle on the underside of the aircraft to provide balanced lift with the 3BSM." F-35 Air Vehicle Technology Overview, page 14

This is a useful comment, but it doesn't provide a full answer to the question.

Read my comments close. As a general rule, yes those doors on top are intakes. However, as the plane moves and gains forward speed, then both the lift fan, and the standard front air intakes are receiving very good airflow. At that point, the air flow from the front intakes and possible the lift fan lid intake are now moving sufficient amounts of air into that intake area - my position is at that point, air pressure will go positive in that intake box area - hence at that point, it becomes a venting system, not a intake system.  That 20,000 lbs thrust with close bottom has to go some place.

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What are the effective span and lifting properties of a circular wing?
Today I read an article on FlightGlobal about the Bell air taxi demonstrator. It includes some paraphrased quotes from the Bell VP of innovation, Scott Drennan, among which the following stood out:

The ducted fans will provide lift during hover, forward propulsion and lift during forward flight, says Drennan. That forward lift will not come from the fans being tilted slightly down, but from the ducts, which act as aerofoils – "circular" wings, engineers call them.

This sounded odd to me for a variety of reasons. I realize this could be the effect of the journalist miss-hearing or miss-quoting the VP, so I'd like to focus on the aerodynamics at play here.
The Bell Nexus air taxi is a quad tiltrotor design with small engine pylons, so cruise lift must come at least in part from the ducted fans, either via downward thrust vectoring or through "duct lift", and the latter presents a slew of issues.
Therefore, the question: what would be the effective lift achievable by a circular wing, or duct without a fan installed in it, in forward flight? In particular, how close would it come to the performance of a regular slender wing of a span equal to the duct diameter. Let us limit the discussion to low-subsonic flight.
Bonus points: what would be the bonus or malus of having a fan installed in such a duct or circular wing, adding its own component to the circulation around the duct walls?

The lift coefficient slope of a planar circular wing is 1.79002303 (to 9 sig. figs.) See, for example,:
Peter F. Jordan, "Exact Solutions for Lifting Surfaces", AIAA Journal, Vol. 11, No. 8, 1973., pp. 1123-1129.
Peter F. Jordan, "On Lifting Wings with Parabolic Tips", ZAMM 54, pp. 463-477, 1974.

@Lysistrata funny you should mention those articles, I printed them out for later reference just yesterday.

I hope that they are useful and that we are talking about the same type of wings. Sometimes "circular wing" means circular planform, sometimes what  I would call a "ring wing".

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text:
What does it cost to get an ATP certificate from scratch?
If someone decides to become a professional pilot - meaning an airline or business jet pilot in the USA - what does it cost to get the certifications and ratings and build enough hours to become employable? Let's assume that the person is starting from scratch and works through private, instrument, commercial and ATP qualifications.
I'm thinking of a scenario where someone already has a career and income but decides to change to flying and is able to invest the necessary time and money. Of course this could include other commercial flying jobs along the way - like crop dusting or banner towing - but the idea would be to eventually reach a position that pays a decent salary. "Decent" isn't very precise but I mean something much higher than the low regional salaries mentioned in this question.

Take into consideration the emotional effect of moving from a senior position into a very junior position. At age 35 my first wife terminated our 16 year marriage, and I decided, what the hell, and decided to go fly. This eventually put me in the right seat of commuter airlines being captained by guys and gals the age of my children. It also put me in the position of having to sit by quietly when captains worried about the possible impact of potential careers with major carriers would do things inimical to the welfare of the commuter airline they were working for at the time. Really maddening.

If you want to keep that love for flying...don't become a professional pilot.

About 4 - 5 years of your life if you're lucky. A marriage if you are not. Plus a few dollars

One thing to consider: a new airline pilot fresh off his ATPL checkride can expect to make just $20,000 a year as the First Officer of a regional jet or turboprop, which is the entry-level position for airlines. If you already have a career that pays well enough for you to get into flying for recreation, the move to professional pilot is a jump off a cliff salary-wise. NetJets pays better (starting salaries about $87k) but you will face very stiff competition. Other opportunities include corporate jet pools and being on a billionaire's personal payroll.

The cost from 0 to ATP can be highly variable.  An easier number to quantify is 0 - Commercial/CFI.
Even the cost of 0 - Comm/CFI can vary, but there are a few accelerated programs that offer this.  One service (I'm not advertising, so I'm not naming them) offers a program that lasts 150 days and costs $65,000* + checkride expenses.  You start with nothing and end up with single/multi commercial, an instrument rating and your CFI/MEI/II along with 100 hours multi-engine time.  This particular program (and others like it probably) hires their instructors from within, so there is a possibility for multi-instruction -- but you won't be making much money for it.
The cost of commercial to ATP is harder to nail down because of the possibilities that open up post-commercial.

On the high end, you could just rent or buy time to ATP mins, but that could cost a fortune.
On the low end you could work to ATP mins and make some money.

A good way to make money with a fresh commercial/cfi ticket is to instruct. There are also jobs like banner towing or pipeline/powerline patrol you could do, but you probably still need to build time beyond commercial mins to be competitive for those jobs.  You also mention cropdusting, but keep in mind many of those ops are turbine powered ag-cats and you won't be competitive there with a fresh commercial ticket.
*You can do it cheaper but I'm giving these numbers because a fast but expensive program may appeal to a career changer.

Well.. There's not a real easy answer to this question.  Starting a career in aviation is no small undertaking.  Large aviation universities like Embry-Riddle really are a good as they say, but the focus is more on getting a degree along side your flying.  Most airlines require a 4 year degree, but they don't care in what field, they just want to know that you have a good foundation and the commitment to complete your higher education.  That said, if you already have a degree, then you might want to shop around for a place that can focus more on flying and less on the classroom.  If you don't have a degree, then you could consider a large Aviation University, but its not cheap, and it might be until retirement to reap the dividends.  Also know, that smaller flight schools run professional pilot programs and can give a more focused study path.
Fair warning, just to get a private,instrument,commercial,multi-engine,ATP certificates will take at least a year if you're highly motivated, but probably longer. Add school, if needed, and you're at 3-4 years before you can even enter the workforce. Then, after recent legislation, the time required to be a co-pilot with an airline has soared, forcing pilot's to find hours elsewhere.  Generally as a flight instructor which could take another year or three to accumulate enough time to get hired by an airline. Finally after you get planted in the right seat of that airliner, it takes another 3 or 4 years of low seniority grunt work to break 30k in pay. Mandatory retirement is now 65. So now after 9-12 years, your finally an airline pilot, but not much time till retirement.  If you want to fly, and have a desire for aviation, then you should have no problem, you just won't get rich.

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text:
What happens if a private pilot's license isn't used for some time?
I have a question about the currency of a Private Pilot's License: if someone obtains a PPL but doesn't fly for a period of time, is there a time after which some conditions or restrictions are imposed?
I'm mainly interested in Europe and the US.

Welcome to the site! Which country are you asking about? Regulations are different in different locations, but these questions are closely related for Europe and the US, respectively.

In the US (under the FAA) there are 2 things that must be maintained (lets assume this is a VFR license).
First there are some basic flight requirements. You don't need an instructor to complete these. It basically boils down to 3 take offs and landings every 90 days to be current to cary passengers. Here is the full legislation.

Sec. 61.57
Recent flight experience: Pilot in command.
(a) General experience.
(1) Except as provided in paragraph (e) of this section, no person may
  act as a pilot in command of an aircraft carrying passengers or of an
  aircraft certificated for more than one pilot flight crewmember unless
  that person has made at least three takeoffs and three landings within
  the preceding 90 days, and--
(i) The person acted as the sole manipulator of the flight controls;
  and (ii) The required takeoffs and landings were performed in an
  aircraft of the same category, class, and type (if a type rating is
  required), and, if the aircraft to be flown is an airplane with a
  tailwheel, the takeoffs and landings must have been made to a full
  stop in an airplane with a tailwheel.
(2) For the purpose of meeting the requirements of paragraph (a)(1) of
  this section, a person may act as a pilot in command of an aircraft
  under day VFR or day IFR, provided no persons or property are carried
  on board the aircraft, other than those necessary for the conduct of
  the flight. (3) The takeoffs and landings required by paragraph (a)(1)
  of this section may be accomplished in a flight simulator or flight
  training device that is--
(i) Approved by the Administrator for landings; and (ii) Used in
  accordance with an approved course conducted by a training center
  certificated under part 142 of this chapter.
(b) Night takeoff and landing experience.
(1) Except as provided in paragraph (e) of this section, no person may
  act as pilot in command of an aircraft carrying passengers during the
  period beginning 1 hour after sunset and ending 1 hour before sunrise,
  unless within the preceding 90 days that person has made at least
  three takeoffs and three landings to a full stop during the period
  beginning 1 hour after sunset and ending 1 hour before sunrise, and-
(i) That person acted as sole manipulator of the flight controls; and
  (ii) The required takeoffs and landings were performed in an aircraft
  of the same category, class, and type (if a type rating is required).
(2) The takeoffs and landings required by paragraph (b)(1) of this
  section may be accomplished in a flight simulator that is--
(i) Approved by the Administrator for takeoffs and landings, if the
  visual system is adjusted to represent the period described in
  paragraph (b)(1) of this section; and (ii) Used in accordance with an
  approved course conducted by a training center certificated under part
  142 of this chapter.

Every 2 years you will also need a flight review which is administered by an instructor.

Sec. 61.56
Flight review.
(a) Except as provided in paragraphs (b) and (f) of this section, a
  flight review consists of a minimum of 1 hour of flight training and 1
  hour of ground training. The review must include:
(1) A review of the
  current general operating and flight rules of part 91 of this chapter;
  and
(2) A review of those maneuvers and procedures that, at the
  discretion of the person giving the review, are necessary for the
  pilot to demonstrate the safe exercise of the privileges of the pilot
  certificate. (b) Glider pilots may substitute a minimum of three
  instructional flights in a glider, each of which includes a flight to
  traffic pattern altitude, in lieu of the 1 hour of flight training
  required in paragraph (a) of this section. (c) Except as provided in
  paragraphs (d), (e), and (g) of this section, no person may act as
  pilot in command of an aircraft unless, since the beginning of the
  24th calendar month before the month in which that pilot acts as pilot
  in command, that person has--
(1) Accomplished a flight review given
  in an aircraft for which that pilot is rated by an authorized
  instructor; and
  (2) A logbook endorsed from an authorized instructor
  who gave the review certifying that the person has satisfactorily
  completed the review. (d) A person who has, within the period
  specified in paragraph (c) of this section, passed a pilot proficiency
  check conducted by an examiner, an approved pilot check airman, or a
  U.S. Armed Force, for a pilot certificate, rating, or operating
  privilege need not accomplish the flight review required by this
  section. (e) A person who has, within the period specified in
  paragraph (c) of this section, satisfactorily accomplished one or more
  phases of an FAA-sponsored pilot proficiency award program need not
  accomplish the flight review required by this section. (f) A person
  who holds a current flight instructor certificate who has, within the
  period specified in paragraph (c) of this section, satisfactorily
  completed a renewal of a flight instructor certificate under the
  provisions in Sec. 61.197 need not accomplish the 1 hour of ground
  training specified in paragraph (a) of this section. (g) A student
  pilot need not accomplish the flight review required by this section
  provided the student pilot is undergoing training for a certificate
  and has a current solo flight endorsement as required under Sec. 61.87
  of this part. (h) The requirements of this section may be accomplished
  in combination with the requirements of Sec. 61.57 and other
  applicable recent experience requirements at the discretion of the
  authorized instructor conducting the flight review. (i) A flight
  simulator or flight training device may be used to meet the flight
  review requirements of this section subject to the following
  conditions:
(1) The flight simulator or flight training device must be
  used in accordance with an approved course conducted by a training
  center certificated under part 142 of this chapter.
(2) Unless the
  flight review is undertaken in a flight simulator that is approved for
  landings, the applicant must meet the takeoff and landing requirements
  of Sec. 61.57(a) or Sec. 61.57(b) of this part.
(3) The flight
  simulator or flight training device used must represent an aircraft or
  set of aircraft for which the pilot is rated.

The license its self (as the laws currently stand) is good for life, barring you having it revoked for some reason you will not need to fly your check ride again (unless you go for something like an instrument rating or a higher license).
Until recently here in the US you also needed a valid medical certificate. However recent regulation change has altered that a bit. You can read up on some of the changes here as they are still in progress.
On a bit of the more practical side there are some things to consider. For example many people here in the US rent aircraft. Your local flight school or rental facility may impose other rules on flight currency for you to be allowed to rent a plane. Likewise if you own a plane your insurance company may require certain experience or other things in order for you to be allowed to fly your plane. Generally this is based on your experience as well as time in type.

It's not a "must" as such to maintain currency per 61.57, it's only required for carrying passengers (although that is relevant to the question about restrictions being imposed after some time). And you might want to mention that you also need a medical certificate.

Edited to reflect your suggestions. The medical is however no longer needed as per recent reforms.

It's a bit premature to say that no medical is required: the FAA hasn't published new regulations yet and even when they do, you'll still need to log an online course every 2 years and get a sign-off from your doctor every 4 years. So pilots will still need some medical documentation, even if it should be much easier to get in future. It's definitely not a driver's license medical.

My apologies I had miss read some of the earlier talks on it a few months back then seen the headlines recently, ill update my answer.

No problem! The AOPA FAQ seems to be a good source for the most current information.

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text:
What is the folded size of a sectional map?
Bending aluminum for a map box, and am curious as to the folded dimension of a sectional chart. My present resources use moving maps on EFIS and iPad, but I would like to carry standard paper charts.

Your best bed is to get an actual chart which runs for less than $10

One seller's link on Amazon claimed 10" x 5", but when I measured an old one (only one I have handy), it was between 10.25" and 10.5" long by 5" wide. So I'd recommend using the latter value, knowing that the chart will probably be a hair under 10.5" long and so you have room for error (or a badly refolded chart).

A Van's map box kit has a 12" depth, my application only allows 11.5". The actual measurement provides positive verification, thanks.


text:
How do pilots of small planes know where to move people?
On a recent flight from Washington, DC to Toronto, the pilot gave very specific directions to rebalance the plane (a Dash-8 IIRC), something like "someone needs to move to seat 11E."
How did he know that putting someone in seat 11E would balance the plane properly? Does the plane weigh itself or is there a computer model somewhere that tells him what to do? Or would an experienced pilot be able to look at the seat chart and know what to do?

Related: Are passengers really not allowed to change seats before take-off due to weight and balance?

Related: How does a commercial airliner measure its weight/mass? This may not answer exactly your question, but will provide what is the process.

Typically an experienced pilot flying a commuter-class aircraft where he can look back and see all of the seats will know if the aircraft is within balance and which seats to fill to balance if it is not. However, a weight & balance must still be calculated and made available on the ground. I stopped flying commuters in the late 1980s, but even then we used programmable calculators to do the calculation. Manual work sheets were also available.

You say a small plane with a seat 11E?  ... I do not think this "small plane" term means what you think it means ;)

Well the seats were ACEF. Should I change it to "small commercial jets"?

@MortensenAviation +1 for The Princess Bride reference!

Depending on the airline, and the size of the aircraft, the Weight and Balance calculations for each flight are either done by the pilots, or by the Flight Operations, Load Department.
If it is done by the pilots, they will receive the loading information which contains the weight and location of all passengers, cargo, and fuel. They then calculate manually, or by using software, the exact center of gravity.
If done by the Load Department, the center of gravity information will be communicated by radio or ACARS datalink.
It is not unusual to require a last minute seating or cargo change in order to ensure the aircraft is within the proper center of gravity limits for takeoff.

I think they use an average accepted adult-human weight, right?  In reality, in airlines, they don't know anything "exactly" weight-wise. Maybe, it's different for regionals or corps.

Depends on the opspecs for the carrier.  The carriers I worked for required actual weights for EVERYTHING.  This means weighing each box (up to 5000lbs of UPS next day freight) and weighting passengers.  If a passenger refused to consent to an actual weight check we could ask their weight and then add 10lbs for use in our W&B calculations.  Most planes with 19 or more seats -or- scheduled passenger carriers use the "FAA standard" weight.  There is a summer and winter "standard" to account for bulkier winter clothes.

See https://en.wikipedia.org/wiki/Air_Midwest_Flight_5481 for details of how the FAA standard weight gets updated...


text:
Is there really a safe for storing secret orders on board a B-52 bomber?
In the movie Dr. Strangelove or How I Learned to Stop Worrying and Love the Bomb, a safe appears at 4:05 (you can see the sequence here).
Is there really a safe on the B-52? If so, is it normal that bomber planes have a safe on board?

I think you could ask this on the Modern Aerial Warfare chat because the question is very much borderline on "on-topic" on this site: http://chat.stackexchange.com/rooms/36081/modern-aerial-warfare

I can only answer for the UK and some other NATO (non-US) aircraft.  There are no safes onboard the aircraft.

@Simon I think it is a curious question, but it is indeed related to aviation in that the question is about aircraft construction and military aviation operations

@Pugz Simon refered to the virst version of the question, which was edited after his comments.

@user3624251 voops, sorry

I'm voting to close this question as off-topic because it is better for Skeptics.SE.

@kevin it is a question about an aircraft, I don't see why it would be OT here.

@kevin The same could be said about just about any question that starts with "is it true that...", but this particular example of the breed relates particularly to aircraft design.  Thus, I think it's in scope.  Voting to re-open.


text:
What is the procedure when an aircraft with an emergency can't land due to a blocked runway?
This is a hypothetical scenario, but I'm interested to know if there are any regulations/guidance for what ATC should do in this situation.
The hypothetical nightmare scenario:

The runway is blocked by a crashed airliner and can't be cleared quickly.
The airliner is full of injured passengers who will take time to move.
The next aeroplane in line to land has an engine failure and is gliding to the runway (so can't go around).
You're in a hilly/built-up area so other options for landing are limited.

Clearly, you can't have one aircraft landing on top of a crashed aircraft, so what should ATC do?
Some of the options I can come up with (in roughly ascending order of how crazy they sound):

Switch him to a different runway e.g. LHR has two parallel runways (but if he's close to the airport making the sudden move across to another runway might be dangerous without power?)
Empty a taxiway (but you'd probably struggle to empty it fast enough at a busy airport?)
Point him towards a grassy bit of the airport
Allow him to land, but aim to land before or after the crashed aircraft (crash is probably at start or end of runway, so might just work)
Wish him good luck and tell him to find somewhere else to land (you know that's possibly going to result in him crashing, but at least he won't crash into the already crashed aircraft).

So is there any advice for the controller and if so what is it?

Note the source of this question was listening to a recording of the ATC when BA38 crashed at LHR. The controller asks the next aircraft to go around - it made me wonder what would happen if they had said no!

Welcome to aviation.SE! There's nothing wrong with hypothetical questions but there's unlikely to be a good, specific answer to this one. As the FAA's ATC orders say, "Because of the infinite variety of possible
emergency situations, specific procedures cannot be
prescribed. [...]  select and pursue a
course of action which appears to be most appropriate
under the circumstances".

@Pondlife thanks - I guess "no, they don't give any advice" is still a valid answer.

Welcome to aviation.SE, as Pondlife said, there is nothing wrong with hypothetical questions but you have essentially created one where there is nothing that can be done. You're question essentially boils down to is there a procedure that says the airliner should crash into the other aircraft or the hills, which IMHO isn't a good question.

Related: May an emergency aircraft land on a closed runway?

You ask "what should ATC do?", but really the question should be "what should the pilot do?" It's the pilot who makes the ultimate decision (example). ATC's job is to ensure aircraft separation through communication.

The closest thing to a procedure, is avoiding it in the first place: fuel reserves so you can at least hold for a bit if not to divert, freezing movements when an emergency is inbound, etc.

@Ben Fuel reserves don't help in the event of an engine failure, though. Having one or more additional engines does help, though. Incidentally, a single engine failure during a go-around is not completely unprecedented, though airliners will usually have enough power remaining with the other engine(s) to go around successfully.

@Ben That said, you're right about the best option being to avoid the scenario in the first place. An airplane crashing into the runway followed by the airplane behind it losing all engines on short final is incredibly unlikely. If the engine failure has already occurred, ATC generally won't be landing other aircraft in front of the emergency aircraft on the runway that they're directing it to. That way, there's no worry about the aircraft in front of the emergency aircraft not being able to vacate the runway in time for the emergency landing.

@200_success In the OP's defense, the aircraft separation is about to get pretty darn cozy, depending on what happens next!

In this particular BA38 case the crash was before runway and the plane stopped at the very end of the runway, so probably the next aircraft could have landed safely, assuming it could slide far enough.

Also related: https://aviation.stackexchange.com/questions/35211/how-are-landing-aircraft-handled-during-an-emergency-runway-closure

Is there a river next to the airport?  ;-)

@reirab: Probably the best chance of this happening is if you replace "airliner" with "large military aircraft" (such as a bomber or a large military transport) and there's a war on; battle damage could easily result in an aircraft crashing on the runway closely followed by another aircraft with no engine power (for instance, from having its fuel tanks damaged and drained).

ATC: ACME123 runway two seven right is closed, cleared to land runway two seven left. ACME123: unable due to a double engine failure. ATC: ACME123 say intentions.

What's the procedure? The procedure is, be creative to save as many lives as possible!
Really. The procedure is to determine a course of action which will likely result in the best outcome for everyone, utilizing all resources and given all constraints. Period. It is as simple as that.
There are infinitely many scenarios, and one cannot be trained for everything. However, pilots and controllers are trained to remain calm. When we look at the accident report years later, reading the document, we can easily say "if the pilots had done that, people would have been saved...". The important thing is that the people who were responsible at the time had to remain calm enough to look at the big picture instead of focusing on a particular problem, otherwise they can easily overlook a solution.
During training, it is common to throw multiple failures / emergencies together. The purpose is not to train the trainee to react to this exact combination of failure, since that is rather unlikely. Rather, the purpose is to simulate a stressful environment, under which one has to make sound and logical decisions.

The airport may be able to deploy an aircraft arresting barrier to stop the incoming flight short on the runway. These are commonly available at joint civil/military fields but there's no reason a major airfield couldn't have one for emergencies.http://www.boeing.com/commercial/aeromagazine/aero_13/runway_story.html

If I had to completely guess, landing over the obstacle and driving off the end, or landing before, hitting the breaks hard, and driving off the side of the runway seem like options that might help a little.

I guess the name of the procedure is JSS, which stands for Just Survive Somehow

No, there is no standard procedure for handling a scenario like the one you describe. It is up to the pilot in command, in cooperation with air traffic control, to decide what to do.
There are generally very few specific procedured defined for handling emergency situations. Handling unusual situations is exactly why there are pilots and air traffic controllers at all. We come up with solutions to problems that no one has ever seen before, or even thought about - it's what we get paid to do. If there was a rule for how to handle every single hypothetical scenario, we would be long gone, replaced by computers. But that is not possible - at least for now.

An example of how the title situation was handled in real life.
UA497 took off from the KMSY (New Orleans International) 2011-04-04 7000 ft runway and 4 minutes after wanted to return. The Longer runway (10104 ft) was closed at the time for lengthy repairs with equipment on the runway.
Pilots wanted the longer runway but it couldn't be cleared in time.
They eventually landed on the 7000 foot runway, and veered a bit off to the side and were stuck for some hours.
http://flightaware.com/resources/airport/MSY/APD/AIRPORT+DIAGRAM/pdf
Overview of aftermath (plane ran off side of runway and took time to clear)
http://www.cnn.com/2011/US/04/04/louisiana.emergency.landing/
"United Airlines pilot, control tower conversation: 8 minutes and 44 seconds of steely calm"
http://www.nola.com/news/index.ssf/2011/04/united_airlines_pilot_airport.html

It's a hypothetical scenario, perhaps, but one that has actually been considered and legislated for in at least one case.
If you're flying to Easter Island, you're not allowed to commit to it until any previous traffic has landed.
As with so many things in aviation, it's a lot easier to get out of this sort of mess when the system prevents you from getting into it in the first place :)

well, that's nice in theory but in the hypothetical case presented here it's either land, ditch, or crash. Wonder what'd the verdict be if a tower controller tells an out of fuel airliner gliding in on Easter Island to divert to the nearest other airport (which is hours away...) because the runway is blocked...

@jwenting: At which point there would certainly be an investigation because ATC won't allow anybody past the midpoint (where Easter Island is now closest) until after the runway is vacated.

Sounds easier to buy a couple of bulldozers and train the ground personnel how to use them "just in case".

Seems reasonable, @RetiredATC, however the hypothetical scenario included a plane blocking the runway and full of already injured pax who couldn't be evacuated in 90 seconds or less.

Like was said, there is no standard for a scenario like that. The pilot in command will take the decision.
If there is another runway or taxiway available to land, the ATC will send the aircraft there.
If none: We start praying and looking for a place to land. After choosing one, we communicate to the ATC in order to send the rescue.

This should be a comment. It does not provide any new information to be considered an answer.

"We start praying and looking for a place to land": You should start with the second option imho.

@mins Procedure agrees with you. Aviate, Navigate, Communicate.

There is a simple rule that allows pilots to do whatever is necessary in an emergency. So what happens in such a case is that the pilot declares an emergency , tries to figure out (together with the ATC) what to do but finally decides on his own what the best possible solution is.
He is allowed to disregard even ATC commands in an emergency (although he is still held responsible for his actions!).
So even though ATC can advice, they're "not the one in charge".
The pilot would most probably land on the blocked runway and turn sideways into the green to not collide with the other airplane.